Question

When 4 J of work is done on a body of mass 2kg such that it starts moving then the velocity is:

Answer 1

Given that F=i-2j, we can say that the acceleration will be a=0.5i-j since a=mFand mass is given to be 2kg in this question. After this, we calculate the velocity after breaking initial velocity V=3i+4j into its components. Thus, in the x-direction, Vx=u(x)+a(x)×t=3+(0.5×4)=5 m/s.

In the y direction,Vy=u(y)+a(y)×t=4−4=0

Therefore we get answer C, which is 5 m/s in the x direction.